Peter White of Peter White Cycles, the U.S. & Canada importer for Wilfried Schmidt, has left a new comment on that post. Since you might not see his comments buried below, here they are:
Some of the early production Edelux headlights don't seal properly. Schmidt will fix any that get water inside. Later production have been 100% trouble free.
If you have a light with water inside, let me know.
Peter Jon White
Peter White Cycles
603 478 0900
Thanks for the update.